This invention relates to electronic steering circuits and more particularly to a directional duplexer suitable for use in omnidirectional scanning antenna systems.
Contemporary scanning antenna systems generally employ a plurality of antenna elements in a circular array to permit 360.degree. coverage. In practice these systems employ mechanical switching systems to enable the simplex transmission or reception of electromagnetic energy over 360.degree. of Azimuth. These mechanical switching systems usually comprise mechanical relays and are not entirely satisfactory. For instance, the lifetime of mechanical relays is relatively short such that the relays must be replaced quite often. Furthermore, the mechanical switching systems are rather complex in nature. The complexity of such systems not only increases the insertion loss of such antenna array systems thereby decreasing antenna gain but also affects the scan rate which is necessarily relatively slow as compared to that of an electronic switching system.
Therefore a need exists for an improved electronic switching system for providing automatic switching of simplex transmission and reception signals or a directional duplexer for providing simultaneous steering of duplex transmission and reception signals.